CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2014						$ (303)
Components of comprehensive income:
Net income	$ 606
Other comprehensive income (loss)	(242)
Ending balance at Jun. 30, 2015						(545)
Beginning balance at Dec. 31, 2015	8,068	$ 0	$ (5,637)	$ 10,242	$ 4,096	(633)
Balance (in shares) at Dec. 31, 2015		1,163	429
Components of comprehensive income:
Net income	463				463
Other comprehensive income (loss)	(16)					(16)
Issuance of common stock pursuant to employee stock options	60			60
Issuance of common stock pursuant to employee stock options (in shares)		4
Issuance of common stock pursuant to restricted stock rights	0			0
Issuance of common stock pursuant to restricted stock rights (in shares)		5
Restricted stock surrendered for employees’ tax liability	(74)			(74)
Restricted stock surrendered for employees' tax liability (in shares)		(2)
Tax benefit associated with employee stock awards	51			51
Stock-based compensation expense related to employee stock options and restricted stock rights	70			70
Stock-based compensation assumed in acquisition	76			76
Dividends ($0.26 per common share)	(193)				(193)
Indemnity on tax attributes assumed in connection with the Purchase Transaction	49		$ 49
Ending balance at Jun. 30, 2016	$ 8,554	$ 0	$ (5,588)	$ 10,425	$ 4,366	$ (649)
Balance (in shares) at Jun. 30, 2016		1,170	429